Hot fill container

ABSTRACT

A hot fill container is provided having a base, a body portion connected to the base, a shoulder portion connected to the body portion, and a neck portion connected to the shoulder portion. At least two panels in the shoulder portion are adapted to flex to accommodate pressure changes within the hot fill container. A longitudinal strut between each of the at least two panels provides longitudinal support to the neck portion.

FIELD OF THE INVENTION

[0001] The present invention relates to a container used for productsintroduced into the container while warm or hot, as appropriate, forsanitary packaging of the product. More particularly, the presentinvention relates to a non-rigid “hot fill” container having flexiblepanels or windows recessed into the shoulder of the container and havinglongitudinal struts separating adjacent panels. The panels are adaptedto flex to accommodate pressure changes within the “hot fill” containerassociated with temperature changes of the product within. The strutsallow the desired panel flexure but prevent excessive and deformingchanges that would compromise container strength and adequate labelattachment surfaces.

BACKGROUND OF THE INVENTION

[0002] Non-rigid containers used for filling processes with warm or hotproducts, so called “hot fill applications”, must address severalfundamental concerns that are not present in conventional containerapplications. A primary concern arises because liquid food products mustbe poured and sealed in a container at an elevated temperature that ishigh enough to destroy bacteria, microorganisms and the like to sustainfood quality. The thin side walls of conventional non-rigid containersthermally distort or collapse at “hot fill” temperatures. Assuming thata non-rigid container can be formed in a configuration that maintainsits shape at the “hot fill” temperature, i.e. “thermally stable”, thecontainer is then subjected to a vacuum that is inherently drawn withinthe sealed or capped container when hot food products cool and contract.The non-rigid container must either withstand the vacuum or collapsewith sufficient deformation to accommodate the vacuum. Therefore, rigidcontainers, such as glass, have traditionally been used in “hot fillapplications”. A need exists for a non-rigid container that withstandsthe pressure changes associated with “hot fill applications”.

[0003] Another concern in “hot fill applications” using non-rigidcontainers is body deformation that impacts container labeling. Existingnon-rigid container configurations substantially retain their overallshape, but the bottles flex their side wall. This in turn requiresspecial labels and/or labeling techniques to be used by the bottler. Intypical glass bottling operations, a light weight paper label is simplyglued onto the bottle as it is rolled after the bottle is hot filled andcapped. The non-rigid side wall configurations of existing non-rigid“hot fill” containers flex and will not hold conventional, glued lightweight paper labels, especially when the vacuum seal is broken and thebottle expands. A need exists for a non-rigid container that withstandsthe pressure changes associated with “hot fill applications” withoutflexing of the side walls.

[0004] U.S. Pat. No. 3,403,804 to Colombo discloses a blown bottle offlexible plastic having a plurality of spaced pairs of grooves 16′around the circumference of the body portion, as shown in FIG. 1. Thegrooves resist radial swelling of the container in the body portion dueto internal gas pressure. However, the container is not able to preventaxial or longitudinal deformation of the container in the neck portion.

[0005] U.S. Pat. No. 3,397,724 to Bolen et al. discloses a thin walledcontainer that is prebulged to avoid bulging of the container whenfilled and allowed to stand, as shown in FIG. 2. Moreover, slightadditional radial deformation of the container is permitted. Thecontainer does not eliminate radial and longitudinal deformation of thecontainer in either the body or neck portions.

[0006] U.S. Pat. No. 3,297,194 to Schaper et al. discloses a containerhaving a plurality of circumferentially extending ribs 28 around themid-section of side wall 14, as shown in FIG. 2, to prevent thecontainer from becoming out of round. However, the ribs allow thecontainer to be compressed during axial loading, and return thecontainer to its original height when the axial load is removed.

[0007] Another concern in “hot fill applications” is that oflongitudinal force loadings on the non-rigid container. Existingbottling operations typically employ star wheel layouts. Non-rigidcontainers are filled in one wheel and transferred to another wheelhaving a capper that screws the closure onto the non-rigid containerwhile the wheel rotates at high speed. The hot fill product is still hotwhen the capping mechanism tightens the closure. The ability of thenon-rigid material to withstand compressive forces is reduced atelevated temperatures. While the capper mechanism can be and has beenaltered to reduce longitudinal force loadings on non-rigid containersand/or non-rigid containers have been altered to provide mouth rings forloading purposes, such factors affect the bottle configuration.Non-rigid containers must have a side wall strength sufficient to permitstacking one on top of the other without collapse. Existing non-rigidcontainers having vacuum panels indented into the side wall do notassist the container in developing sufficient longitudinal strength toresist deformation. Moreover, vacuum panels in the neck portion of thenon-rigid container do not prevent changes in the height of the overallcontainer due to longitudinal deformation of the vacuum panels in theneck portion of the container. A need exists for a hot fill containerthat has sufficient strength to resist longitudinal deformation due tolongitudinal loading and deformation caused by the vacuum associatedwith “hot fill applications”.

[0008] U.S. Design Pat. Nos. D225,510 to Strand; D218,020 to Musson;D219,129 to Wood; D195,371 to Torongo; D294,462 to Ota et al.; D295,499to LeFevre; D278,682 to Khalifa; and D70,732 to Dengler et al. disclosecontainers having panels in the neck portion. However, none of thepatents disclose means to prevent longitudinal deformation of thecontainers due to longitudinal loading and deformation caused by thevacuum associated with “hot fill applications”.

[0009] U.S. Pat. No. 5,067,622 to Garver et al. discloses a container 70having vacuum panels 83 recessed in the neck segment 81, as shown inFIG. 4, that deflect radially when a vacuum is drawn in the container.The panels 83 in combination with the bulbous neck segment 81 preventboth radial and longitudinal contraction of the body portion 77 of thecontainer. However, nothing prevents longitudinal contraction of theneck segment 81 when a vacuum is drawn in the container.

[0010] A need exists for a non-rigid hot fill container that does notlose its shape or height due to pressure changes associated with hotfill applications of non-rigid containers.

SUMMARY OF THE INVENTION

[0011] Accordingly, it is a primary objective of the present inventionto provide a non-rigid container for products filled while warm or hotwherein the container resists deformation due to pressure increases orreductions as the “hot fill” product cools or is heated.

[0012] Another objective of the present invention is to provide anon-rigid container for hot fill applications that resists flexing ofthe container side walls due to pressure changes within the containerassociated with hot fill applications.

[0013] Another objective of the present invention is to provide anon-rigid container for hot fill applications that resists longitudinaldeformation due to pressure changes within the container associated withhot fill applications.

[0014] The foregoing objects are basically attained by providing anon-rigid hot fill container having a base, a body portion connected tothe base, a shoulder portion connected to the body portion, and a neckportion connected to the shoulder portion. At least two panels in theshoulder portion are adapted to flex to accommodate pressure changeswithin the hot fill container. A longitudinal strut between each of theat least two panels provides longitudinal support to the neck portion.

[0015] Other objects, advantages and salient features of the inventionwill become apparent from the following detailed description, which,taken in conjunction with the annexed drawings, discloses preferredembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Referring now to the drawings that form a part of the originaldisclosure:

[0017]FIG. 1 is a perspective view of a non-rigid hot fill containeraccording to the present invention;

[0018]FIG. 2 is a perspective view of the container of FIG. 1 showingthe base of the hot fill container;

[0019]FIG. 3 is a front elevation view of the container of FIG. 1;

[0020]FIG. 4 is a top view of the container of FIG. 1;

[0021]FIG. 5 is a bottom view of the container of FIG. 1;

[0022]FIG. 6 is an enlarged front elevation view of the panels andstruts of the container of FIG. 1 and without a cap on the neck portionof the container;

[0023]FIGS. 7-9 are diagrams showing flexing of the panels of thepresent invention between the initial temperature at which the hot fillproduct is introduced to the non-rigid hot fill container and the finaltemperature at which the product has cooled.

DETAILED DESCRIPTION OF THE INVENTION

[0024] As seen in FIGS. 1-9, the non-rigid hot fill container 21 of thepresent invention has a base 31, a body portion 41 connected to thebase, a shoulder portion 51 connected to the body portion, and a neckportion 61 connected to the shoulder portion. At least two panels 71recessed into the shoulder portion are adapted to flex to accommodatepressure changes within the non-rigid hot fill container 21 associatedwith hot fill applications. A longitudinal 81 strut between each of theat least two panels 71 provides longitudinal support to the shoulderportion 51 and the neck portion 61.

[0025] The base 31 provides support for the container 21. Preferably, asshown in FIGS. 2 and 5, the base is substantially circular. The base 31has a substantially planar portion 33 providing support for thecontainer. A concave portion 35 has a plurality of ribs 37 to providelateral and longitudinal strength to the container. As shown in FIGS. 2and 5, the concave portion 35 preferably has six ribs 37.

[0026] A body portion 41 extends upwardly from an outer edge 29 of thebase 31 to an upper lip 46 of the body portion. The body portion 41 issubstantially perpendicular to the base. The body portion 41 includes aplurality of flat portions 43, as shown in FIG. 3. A ribbed portion 45separates each flat portion. Each flat portion 43 has a width “f”, asshown in FIG. 3. Each ribbed portion 45 has a width “r”, as shown inFIG. 3. Preferably, the width “f” of each flat portion is twice thewidth “r” of each ribbed portion. Flat portions 43 having a width largerthan the width of the ribbed portions 45 provides a body portion havinga larger surface area, which allows for better label adhesion.Additionally, the smaller width of the ribs prevents label distortionwhen the container 21 is handled after the label has been affixed to thecontainer. Preferably, the label is affixed over the width “l” on thebody portion 41, which is denoted by lines 42 and 44 of FIG. 3. The ribs43 also prevent radial deformation of the body portion 41 of thecontainer due to pressure changes in the container associated with hotfill applications, e.g., the hoop stress induced in the body portion dueto the vacuum caused by the temperature drop of the hot fill product.

[0027] A shoulder portion 51 extends upwardly from the upper lip 46 ofthe body portion 41 of the container 21, as shown in FIGS. 3 and 6.Preferably, the shoulder portion 51 tapers inwardly as it extendsupwardly from the body portion 41, thereby forming a frustoconicalconfiguration. The degree of taper θ may be between 0 and 89 degrees,inclusive, as shown in FIG. 6. A plurality of flex panels 71 arepositioned around the circumference of and recessed into the shoulderportion 51. Each flex panel 71 is separated from the adjacent flex panelby a longitudinal strut 81. The flex panels 71 and longitudinal struts81 extend upwardly from the upper lip 46 of the body portion 41 to thecurved lip 53 of the shoulder portion 51. The curved lip 53 issubstantially C-shaped and extends outwardly from the longitudinal axis23 of the container 21 before extending inwardly to meet the bottom edge63 of the neck portion 61.

[0028] The flex panels 71 have an upper width “UW” and a lower width“LW”, as shown in FIG. 6. Preferably, the upper width and the lowerwidth of the flex panels 71 are not equal, as shown in FIG. 6. Theinitial configuration of the flex panels 71 has a convex curvature, asshown in FIGS. 6 and 7. The flex panel 71 has a radius from thelongitudinal axis that is greater at the middle 73 than at the upper andlower end points 75 and 77, respectively, as shown in FIG. 7. The dashedline 79 shown in FIGS. 7-9 corresponds to a line between the upper endpoint 75 and the lower end point 77 of the flex panel 71 that isparallel to the taper θ of the shoulder portion 51, i.e., a flat panel.Preferably, there are between four and six flex panels 71 around thecircumference of the shoulder portion 51. Preferably, the edge 72 of theflex panel 71 may have an initial concave curve 74 before curvingconvexly 76 at the center of the panel to provide greater flexibility.The flex panels 71 may be symmetrically or asymmetrically space aroundthe circumference of the shoulder portion 51.

[0029] The longitudinal struts 81 extend from the upper lip 46 of thebody portion to the curved lip 53 of the shoulder portion 51, as shownin FIGS. 1, 3 and 6. The longitudinal struts 81 separate each of theflex panels 71 and allow the panels to flex independently of the struts.Preferably, there are an equal number of struts and flex panels aroundthe circumference of the shoulder portion, i.e., four-six struts. Thelongitudinal struts 81 resist longitudinal loading (verticalcompression) introduced by the capping and sealing process. Furthermore,the longitudinal struts 81 maintain the height of the container 21 bypreventing longitudinal and lateral movement of the shoulder portion 51when the flex panels 71 flex to accommodate internal pressure changesassociated with hot fill applications.

[0030] Preferably, the strut height “SH” is approximately equal to105-125% of the panel height “PH”, as shown in FIG. 6. Preferably, thestrut width “SW” is approximately equal to 5-100% of the panel lowerwidth “LW”. More preferably the strut width is approximately 5-25% ofthe panel lower width. Preferably, the upper width “UW” of the flexpanel 71 is approximately equal to 90% of the lower width “LW”.Preferably, the lower width “LW” is approximately 110% of the panelheight “PH”.

[0031] A neck portion 61 extends upwardly from edge 63 of the neckportion 61 to the top edge 64 of the neck portion, as shown in FIGS. 3and 6. The neck portion 61 has an outer surface 65 that has externalthreads 67, as shown in FIG. 6. The neck portion 61 has an opening 68for introducing hot fill product into the container. Preferably, thediameter of the opening 68 is at least 38 mm, but it may be any diametersuitable for the hot fill application. The step-down recess from theshoulder portion 51 into the perimeter of the neck portion 61 maintainsthe strength of the neck portion, as shown in FIG. 3.

[0032] A cap 69 has internal threads for threading onto neck portion 61of the container 21 to seal the hot fill product within the container. Aneck shoulder 66 provides a stop for the cap 69.

[0033] Assembly and Operation

[0034] Preferably, the base 31, body portion 41, shoulder portion 51,neck portion 61, panels 71 and struts 81 are unitarily formed. The hotfill container 21 is made of a non-rigid material, preferably PET(polyethylene terephtlate).

[0035] Typically, during hot fill applications, a hot fill product isintroduced into the container 21 at an initial temperature (To) ofapproximately 185 degrees Fahrenheit (85 degrees Celsius). Once thecontainer has been filled with the hot fill product to a predeterminedlevel, a cap 69 is secured to the container 21, preferably by threadingthe cap onto the externally threaded neck portion, to seal the hot fillproduct within the container. The initial configuration of the flexpanels 71 when the container is sealed at T_(O) is shown in FIG. 7.

[0036] As the temperature of the hot fill product begins to cool, thepressure in the headspace above the liquid within the container 21begins to drop. As the temperature of the hot fill product continues todrop toward ambient temperature, the air pressure within the container21 also continues to decrease. To offset the pressure drop within thecontainer 21, the panels 71 begin to flex inwardly to accommodate thepressure drop, as shown in FIGS. 8 and 9. As shown in FIG. 8 at anintermediate temperature (T₁) of approximately 110 degrees Fahrenheit(43 degrees Celsius), the panels 71 have flexed inwardly slightly,thereby approaching being a planar flex panel as indicated by dashedline 79. As shown in FIG. 9, when the temperature of the hot fillproduct has finished dropping and reached ambient temperature, a finaltemperature T_(F) of approximately 72 degrees Fahrenheit (22 degreesCelsius), the panels 71 have finished flexing to accommodate thepressure drop within the container. At the final temperature, T_(F), thepanels 71 have flexed such that there is now a concave curvature at amidpoint 73 of the panel, as shown in FIG. 9. The panels 71 have movedbeyond the planar surface indicated by dashed line 79 to accommodate thepressure drop within the container 21 and to maintain the overall shapeof the container. Furthermore, the flexing of the panels 71 toaccommodate the pressure drop prevents deformation of the body portion41 of the container so that label affixed to the body portion remainsunaffected.

[0037] The longitudinal struts 81 prevent longitudinal flexing of thepanels 71 during the cooling of the hot fill product, thereby ensuringthat the overall height of the container 21 remains unchanged. Thisfacilitates stacking of the containers since the top surface 62 of thecap 69 remains parallel to the planar surface 33 of the base 31.Moreover, the longitudinal struts 81 provide longitudinal strength tothe container 21 to prevent buckling of the container during the cappingprocess.

[0038] While advantageous embodiments have been chosen to illustrate theinvention, it will be understood by those skilled in the art thatvarious changes and modifications may be made therein without departingfrom the scope of the invention as defined in the appended claims.

What is claimed is:
 1. A hot fill container, comprising: a base; a body portion connected to said base and extending longitudinally therefrom; a shoulder portion connected to said body portion; a neck portion connected to said shoulder portion; at least two panels in said shoulder portion adapted to flex to accommodate pressure changes within said hot fill container; and a longitudinal strut between each of said at least two panels to prevent longitudinal flexing of said at least two panels.
 2. A hot fill container according to claim 1, wherein said body portion has a plurality of flat portions.
 3. A hot fill container according to claim 2, wherein said plurality of flat portions are separated by ribbed portions.
 4. A hot fill container according to claim 3, wherein each of said ribbed portions has a first width, each of said plurality of flat portions has a second width, and said first width is substantially one half said second width.
 5. A hot fill container according to claim 1, wherein said neck portion has a diameter of at least 38 millimeters.
 6. A hot fill container according to claim 1, wherein each of said at least two panels has a first edge having a first width and a second and opposite edge having a second width, said first and second widths not being equal.
 7. A hot fill container according to claim 1, wherein said shoulder portion is tapered.
 8. A hot fill container according to claim 7, wherein said taper has an angle between 1 and 89 degrees, inclusive.
 9. A hot fill container according to claim 1, wherein said base is circular.
 10. A hot fill container according to claim 1, wherein said neck portion is threaded for receiving a cap.
 11. A hot fill container according to claim 1, wherein said at least two panels comprises between four and six panels, inclusive.
 12. A hot fill container according to claim 1, wherein said base, said body portion, said shoulder portion, said neck portion, said at least two panels and said longitudinal struts are unitarily formed.
 13. A hot fill container according to claim 1, wherein said base, said body portion, said shoulder portion, said neck portion, said at least two panels and said longitudinal struts are made of PET.
 14. A hot fill container according to claim 1, wherein said at least two panels are substantially rectangular.
 15. A hot fill container according to claim 14, wherein said at least two panels have a concave curve at an edge and a convex curve at a center of said at least two panels.
 16. A hot fill container, comprising: a base; a body portion connected to said base, said body portion having a plurality of flat portions and a ribbed portion separating each of said flat portions; a tapered shoulder portion connected to said body portion; a neck portion connected to said shoulder portion, said neck portion having a threaded external surface to receive a cap; at least two panels in said shoulder portion adapted to flex to accommodate pressure changes within said hot fill container; and a longitudinal strut between each of said at least two panels to prevent longitudinal flexing of said at least two panels, wherein said base, said body portion, said shoulder portion, said neck portion, said at least two panels and said longitudinal struts are unitarily formed.
 17. A hot fill container according to claim 16, wherein said base, said body portion, said shoulder portion, said neck portion, said at least two panels and said longitudinal struts are made of PET
 18. A hot fill container according to claim 16, wherein each of said ribbed portions has a first width, each of said plurality of flat portions has a second width, and said first width is one half said second width.
 19. A hot fill container according to claim 16, wherein said neck portion has a diameter of at least 38 millimeters.
 20. A hot fill container according to claim 16, wherein each of said at least two panels has a first edge having a first length and a second and opposite edge having a second length, said first and second lengths not being equal.
 21. A hot fill container according to claim 16, wherein said tapered shoulder portion has an angle between 1 and 89 degrees, inclusive.
 22. A hot fill container according to claim 16, wherein said base is circular.
 23. A hot fill container according to claim 16, wherein said at least two panels comprises between four and six panels, inclusive
 24. A hot fill container according to claim 16, wherein said at least two panels are substantially rectangular.
 25. A hot fill container according to claim 14, wherein said at least two panels have a concave curve at an edge and a convex curve at a center of said at least two panels. 